Django如何实现多数据库支持及读写分离机制？

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1. 配置多个数据库连接：pythonDATABASES={ 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), }, 'db2': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': os.path.join(BASE_DIR, 'db2.sqlite3'), }}

1.多个数据库

• settings.py

DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), }, 'db2': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': os.path.join(BASE_DIR, 'db2.sqlite3'), }, }

• 迁移其他的数据库

python manage.py migrate --database db2

2.读写分离

2.1手动指定

models.Student.objects.using('db2').all() obj = models.Student.objects.using('db2').get(name='zhazha') obj.name = 'star' obj.save(using='default')

2.4自动选择

• settings配置:

DATABASE_ROUTERS = ['myrouter.Router']

• 创建 router.py

class Router: """ 读写分离 """ def db_for_write(self, model, **kwargs): return 'db2' def db_for_read(self, model, **kwargs): return 'default'

• 一主多从

class Router: """ 一主多从 """ def db_for_write(self, model, **kwargs): return 'db1' def db_for_read(self, model, **kwargs): return random.choices['db2', 'db3', 'db4']

• 分库分表

class Router: """ 分库分表 app01 model db1 app02 model db2 """ def db_for_write(self, model, **kwargs): app_name = model._meta.app_label if app_name == 'app01': return 'db1' elif app_name == 'app02': return 'db2' def db_for_read(self, model, **kwargs): app_name = model._meta.app_label if app_name == 'app01': return 'db1' elif app_name == 'app02': return 'db2'